The demand for high protein foods is a well-known fact in which several protein sources are used of which major contribution arises from plant sources. The technological advances concerning the creation of a new texture particularly using soybean protein have lead to the development of texturised vegetable protein (TVP) or texturised plant protein (TPP) or meat analogue or soya chunk which basically formed the man made food popularly known as fabricated foods or engineering foods. The use of an extruder under appropriate pressure-shear-temperatures combination yields a product that is fibrous in nature, filamentary in structure, and toughness and chewy texture of meat. This whole process is called thermoplastic extrusion. The advantages of this technology lie in low product cost mainly because the raw material to be used is defatted soy flour that is low in cost. In addition, the abundance of defatted soy flour in concert with technological advantages of extrusion cooking have made this type of product popular among several types of people including those who can hardly afford the high cost of animal protein.
The thermoplastic extrusion process involves the preparation of defatted soy flour-water mixture along with other ingredients followed by feeding the mixture into a cooking extruder wherein it is subjected to heat, shear and pressure. When this cooked viscoelastic mass comes out of a restriction, conventionally known as die, the fibrous expanded structure is formed which solidifies to hard texture on cooling or drying. On rehydration and cooking, the fibrous TVP can provide a texture/bite and a mouth feel comparable to cooked meat. It may be mentioned here that the process of producing TVP and similar products are covered under several patents that are discussed in the subsequent sections.
References may be made to an U.S. Pat. No. 3,911,157 (1975) in which claims have been on a process for preparing texturised vegetable protein from non-textured vegetable materials. The process comprises forming a dough from a source of vegetable protein and water; roll milling the dough to a sheet thickness of 18 mils or less to effect cellular disruption and expose coagulable protein molecules; and cooking the sheeted protein at from 180 to 300° F. in the presence of a non-drying atmosphere of moist steam. The texturized protein is especially adapted to use as an extender for comminuted meat items.
References may be made to a British patent GB2108511 (1983) in which a process for low-cost texturised vegetable protein has been described. A textured protein product having a protein content of up to 80% is produced by mixing soy meal (grits, flakes or flour) with water containing a protein insolubilizing agent to prepare a homogeneous mass; forming from said mass discrete pieces of a desired configuration under temperature and pressure conditions which retain the proteins in the undenatured state and retain the protein in carbohydrate molecules thereof substantially in the original matrix relationship of the starting material; and cooking the pieces in water in order (1) to denature the proteins in situ whereby contiguous protein molecules interlock to form a three dimensional network structure throughout each of the pieces, and (2) to leach out soluble carbohydrates from within the protein structure.
Reference may be made to U.S. Pat. No. 4,369,195 (1983) in which extrusion texturization of full-fat soybean and products thereof have been described. A textured soybean product is produced from full-fat soybean by hydrating whole soybean by treatment with a dilute alkaline solution; mixing the hydrated soybean with full-fat soy flour and equilibrating the moisture content thereof; and passing the mixture through an extrusion cooker. The textured product has excellent flavor, color, and appearance, and can be formulated into an all-vegetable ground meat analogue or it can be used as an extender in blends with ground meat.
The drawbacks of TVP are that they are not in the ready-to-eat form as it is mandatory to cook the same prior to consumption. Sometimes, even the hydrated TVPs offer a too hard or chewy texture that is undesirable from the point of consumer acceptability.
References may be made to a European patent EP0517458 (1992) wherein claim has been made for a process for the production of a protein granule suitable for use as a meat extender using a vegetable protein isolate as the raw material. The isolate is hydrated to a ratio of 2 to 3.5 parts of water to 1 part of isolate, wherein the water is at a temperature of at least 50° C. The hydrated isolate is then blended under conditions of shear for a period of time sufficient to form a hydrated protein granule. The formed granules are highly suitable as an extender for ground meats or as an ingredient in meat analogues. The raw materials used here are different from that of the present invention, and an isolate is too costly. Further, the process of preparation is entirely different from the present one.
References may be made to U.S. Pat. No. 5,626,899 (1997) wherein a process for making vegetable-based meat extenders has been claimed. A vegetable protein crumble for use as a meat extender to replace portions of lean and/or fat is made from one part soy protein isolate hydrated in about 3.5-5.0 parts water at ambient temperature and then chopped. A vegetable protein and/or complex carbohydrate is added to the resulting mixture, and again chopped. Then the resulting composition is cooled overnight before being chopped or ground into crumbles. By way of example, a use of the crumble is described as a meat extender in pepperoni. The raw materials used here are different from that of the present invention, and an isolate is too costly. Further, the process of preparation is entirely different from the present one.
Reference may be made to European Patent EP19900103415 (1983) wherein a method of processing whole soybeans to produce discrete, irregularly-shaped chunks or pieces of textured proteinaceous material which are free from off-flavors and odors and have a meat-like texture and appearance is described. Whole soybeans are hydrated and acidified to a pH in the range of about 4.5 to 6.5 and the pH of the soybeans is maintained in this range throughout processing. The acidified whole soybeans are ground in an aqueous medium to provide an aqueous slurry or dough of soybean particles having a pH in the range of 4.5-6.5. The aqueous acidic slurry or dough is passed through a confined treatment zone in which high temperature pressurized steam is injected directly into a confined stream of the slurry or dough under conditions which effect texturization of the soy protein in the form of discrete chunks or pieces which are discharged from the treatment zone. The texturized pieces, when discharged from the treatment zone or when dried and rehydrated are free of off-flavors and odors and have a meat-like texture, firmness and appearance. They are suitable for use in a wide variety of food products, including frozen products, canned products and dry mix products. If desired, additives such as flavoring, coloring, fat, seasoning and other proteinaceous materials may be incorporated in the texturized soy protein pieces. The raw material used here is different from that used in the present claim. The drawback of this process lies in using acids for pH adjustment, and need further treatment to get rid of the same.
Reference may be made to a European Patent EP0385266 (1990) where a method of producing simulated meat product from whole soybeans is disclosed. Whole soybeans has been used to produce discrete, irregularly-shaped chunks or pieces of textured proteinaceous material which are free from off-flavors and odors and have a meat-like texture and appearance. Whole soybeans are hydrated and acidified to a pH in the range of about 4.5 to 6.5 and the pH of the soybeans is maintained in this range throughout processing. The acidified whole soybeans are ground in an aqueous medium to provide an aqueous slurry or dough of soybean particles having a pH in the range of 4.5-6.5. The aqueous acidic slurry or dough is passed through a confined treatment zone in which high temperature pressurized steam is injected directly into a confined stream of the slurry or dough under conditions which effect texturization of the soy protein in the form of discrete chunks or pieces which are discharged from the treatment zone. The texturized pieces, when discharged from the treatment zone or when dried and rehydrated are free of off-flavors and odors and have a meat-like texture, firmness and appearance. They are suitable for use in a wide variety of food products, including frozen products, canned products and dry mix products. If desired, additives such as flavoring, coloring, fat, seasoning and other proteinaceous materials may be incorporated in the texturized soy protein pieces. The raw material used here is different from that used in the present claim. The drawback of this process lies in using acids for pH adjustment, and need further treatment to get rid of the same.
The present invention relates to a process for the development of multipurpose ready-to-use high-protein soy granules from texturised vegetable protein.